This invention relates to an operating lever apparatus used in an electric apparatus in which various modes are established in accordance with various electric signals produced by signal generating means, and having a function to cause the signal generating means to produce those electric signals.
Conventionally, an operating lever apparatus is provided with members which move along a direction to intersect a base plate so that various modes may be established in an electric apparatus by various electric signals produced by such cross motion of the members. The operating lever apparatus of this type, however, requires relatively complicated assembly, having difficulty in enjoying reduced manufacturing cost. Since the members which move in the direction to intersect the base plate are relatively low in force transmissibility, the operation of the operating lever apparatus requires a comparatively great force. The conventional operating lever apparatus is subject to a further drawback in that it is difficult to reduce the dimension of the electric apparatus along the direction intersecting the base plate. These drawbacks are particularly apparent in the case where the electric apparatus using the operating lever apparatus finds its essential selling point in compactness and hence in portability. As an example of such an electric apparatus, there is a tape recorder using what is called a micro cassette.
In the prior art operating lever apparatus, moreover, urging means for biasing the members or operating levers are arranged on the base plate. In many cases, such urging means are conventionally formed of compression coil springs. The dimension of a compression coil spring along the direction intersecting the base plate is larger than that of a leaf spring or torsion coil spring, comparatively. The urging means formed of compression coil springs, therefore, constitute a hindrance to the reduction of the size of the electric apparatus along the direction intersecting the base plate. These drawbacks are quite apparent again in the case where the electric apparatus using the operating lever apparatus finds its essential selling point in compactness and hence in portability.
In the prior art operating lever apparatus, furthermore, a slot extending along the moving direction of the operating levers is formed in each of the operating levers, and a pin planted on the base plate is fitted in the slot. Each operating lever is guided in movement between its first and second positions by the pin in slide contact with the peripheral surface of the slot. In order to prevent the operating levers from being reduced in strength due to the formation of the slots therein, the dimension of the operating levers of the conventional operating lever apparatus along the direction of the width of the slots cannot help being relatively large. Accordingly, it is difficult to reduce the dimension of the conventional operating lever apparatus along the direction of the width of the slots. This is also a drawback in the case where the electric apparatus using the operating lever apparatus finds its essential selling point in compactness and hence in portability.
In the prior art operating lever apparatus, moreover, the base plate and members for guiding the operating levers in movement are formed of opaque material, so that it is hard visually to perceive the operation of the operating levers. Accordingly, detection of defective parts, if any, of the operating lever apparatus during a performance test directly after assembly thereof or in case of malfunction should be a hard task. This also is a drawback especially in the case where the electric apparatus using the operating lever apparatus finds its essential selling point in compactness and hence in portability.